Ft = mu - mv
since u = 0, Ft = mv,
v = $\frac{720\times 0.1}{0.6}$
= 120 m/s
johnmulu answered the question on February 14, 2017 at 07:04
- A trolley is moving at a uniform speed along a track. A piece of plasticine is dropped on the trolley and sticks on it. Explain why the trolley slows down(Solved)
A trolley is moving at a uniform speed along a track. A piece of plasticine is dropped on the trolley and sticks on it. Explain why the trolley slows down.
Date posted: February 14, 2017. Answers (1)
- A high jumper usually lands on thick soft mattress. Explain how the mattress helps in reducing the force of impact(Solved)
A high jumper usually lands on thick soft mattress. Explain how the mattress helps in reducing the force of impact.
Date posted: February 14, 2017. Answers (1)
- An industrial trolley of mass 20 kg carrying a mass of 50 kg is acted on by a constant force. The trolley moves along a horizontal smooth surface with an acceleration of 0.5ms-2(Solved)
An industrial trolley of mass 20 kg carrying a mass of 50 kg is acted on by a constant force. The trolley moves along a horizontal smooth surface with an acceleration of 0.5 ms-2. Determine the acceleration of the trolley after the mass falls off.
Date posted: February 14, 2017. Answers (1)
- A gun is fired vertically upwards from the top of an open truck moving horizontally, uniform velocity of 50ms-1. The bullet achieves a maximum height of 45 m(Solved)
A gun is fired vertically upwards from the top of an open truck moving horizontally, uniform velocity of 50ms-1. The bullet achieves a maximum height of 45 m.
i) State with reason whether or not the bullet will land on the truck
ii) Calculate the distance covered by the truck just before the bullet reaches the level from which it was fired. (Use g = 10 ms-2)
Date posted: February 14, 2017. Answers (1)
- A trolley is moving at constant speed in friction compensated track. Some plasticine is dropped on the trolley and sticks on it. State with a reason what is observed about the motion of the trolley.(Solved)
A trolley is moving at constant speed in friction compensated track. Some plasticine is dropped on the trolley and sticks on it. State with a reason what is observed about the motion of the trolley.
Date posted: February 14, 2017. Answers (1)
- State Newton's first law of motion(Solved)
State Newton's first law of motion.
Date posted: February 14, 2017. Answers (1)
- A nail at the bottom of a beaker containing glycerine appears to be 6.8 cm below the surface of glycerine. Determine the height of the column of glycerine in the beaker(Solved)
A nail at the bottom of a beaker containing glycerine appears to be 6.8 cm below the surface of glycerine. Determine the height of the column of glycerine in the beaker. (Take the refractive index of glycerine as 1.47)
Date posted: February 14, 2017. Answers (1)
- A water wave of wavelength 18 mm is incident on a boundary of shallow water at right angles. If the wavelength in the shallow end is 14.4 mm(Solved)
A water wave of wavelength 18 mm is incident on a boundary of shallow water at right angles. If the wavelength in the shallow end is 14.4 mm, Determine the refractive index of water for a wave moving from the deep to the shallow end.
Date posted: February 14, 2017. Answers (1)
- Determine the speed of light in water given that the speed of light in air is 3.0 x 108 ms-1 and the refractive index of water is 1.33(Solved)
Determine the speed of light in water given that the speed of light in air is 3.0 x 108 ms-1 and the refractive index of water is 1.33.
Date posted: February 14, 2017. Answers (1)
- One of the conditions for total internal reflection to occur is that angle of incidence must be greater than the critical angle of the medium. State the other condition(Solved)
One of the conditions for total internal reflection to occur is that angle of incidence must be greater than the critical angle of the medium. State the other condition.
Date posted: February 14, 2017. Answers (1)
- A small object lies at the bottom of a water pond at a depth of 1.2 m. Given that the refractive index of water is 1.3(Solved)
A small object lies at the bottom of a water pond at a depth of 1.2 m. Given that the refractive index of water is 1.3, Determine the apparent depth of the object. (Give your to 1 decimal place)
Date posted: February 14, 2017. Answers (1)
- Light travels through glass of refractive index 1.5 with a speed V. Calculate the value of V. (Speed of light in air = 3.0 x 108m/s)(Solved)
Light travels through glass of refractive index 1.5 with a speed V. Calculate the value of V. (Speed of light in air = 3.0 x 108m/s)
Date posted: February 14, 2017. Answers (1)
- A stone thrown vertically upwards reaches a height of 100 m. Determine the(Solved)
A stone thrown vertically upwards reaches a height of 100 m. Determine the:
i) Initial velocity of the stone
(Neglect air resistance and take g = 10ms-2)
ii) Total time the stone is in air.
Date posted: February 14, 2017. Answers (1)
- A ball of mass 200 g is thrown vertically upwards with velocity of 5ms-1. The air resistance is 0.4 N. Determine(Solved)
A ball of mass 200 g is thrown vertically upwards with velocity of 5 ms-1. The air resistance is 0.4 N. Determine:
i) The net force on the ball as it moves up;
ii) The acceleration of the ball;
iii) The maximum height reached by the ball,
(take acceleration due to gravity g = 10 ms-2)
Date posted: February 14, 2017. Answers (1)
- A particle starts from rest and accelerates uniformly in a straight line. After 3 seconds it is 9 m from the starting point(Solved)
A particle starts from rest and accelerates uniformly in a straight line. After 3 seconds it is 9 m from the starting point. Determine the acceleration of the particle
Date posted: February 14, 2017. Answers (1)
- A trolley moving on a horizontal bench of height 1.2 m, strikes a barrier at the edge of the bench. The brass mass on the top of the trolley flies off on impact and lands(Solved)
A trolley moving on a horizontal bench of height 1.2 m, strikes a barrier at the edge of the bench. The brass mass on the top of the trolley flies off on impact and lands on the ground 2.5 m from the edge of the bench. Determine:
i) The time taken by the brass mass to reach the ground
ii) The speed at which the trolley struck the barrier.
Date posted: February 14, 2017. Answers (1)
- A matatu starts from rest and accelerates to cover a distance of 49 m in 7 seconds. Determine: ( i) Its acceleration ( ii) Its velocity after 7 seconds(Solved)
A matatu starts from rest and accelerates to cover a distance of 49 m in 7 seconds. Determine:
i) Its acceleration;
ii) Its velocity after 7 seconds
Date posted: February 14, 2017. Answers (1)
- A particle starts from rest and accelerates uniformly in a straight line. After 3 seconds it is 9m from the starting point(Solved)
A particle starts from rest and accelerates uniformly in a straight line. After 3 seconds it is 9m from the starting point. Determine the acceleration of the particle.
Date posted: February 11, 2017. Answers (1)
- A bullet is fired horizontally from a platform 15 m high. If the initial speed is 300 m/s-1(Solved)
A bullet is fired horizontally from a platform 15 m high. If the initial speed is 300 m/s-1, determine the maximum horizontal distance covered by the bullet.
Date posted: February 11, 2017. Answers (1)
- A bullet moving at a velocity of 300 ms-1 hits a tree trunk of diameter 50 cm. It emerges from the opposite side with a velocity of 150 ms-1(Solved)
A bullet moving at a velocity of 300 ms-1 hits a tree trunk of diameter 50 cm. It emerges from the opposite side with a velocity of 150 ms-1. Determine the average deceleration of the bullet in the trunk.
Date posted: February 11, 2017. Answers (1)