A ball is projected horizontally from the top of a cliff on the surface of the earth with a speed of 40 ms-1. Assuming that there is no air resistance, what will be its speed after 3s?
Correct answer: C. 50 ms-1
- A. 30 ms-1
- B. 40 ms-1
- C. 50 ms-1
- D. 60 ms-1
Explanation
The horizontal component of velocity remains constant throughout the motion, vertical component is initially zero. The value of vertical component after 3s can be calculated using equation V = U + at Where V is the final velocity after 3s and U is the initial velocity which is zero. Substitute only y-components in this equation.V = U + at V = 0 + (10)(3)V = 30 m/sHorizontal component is 40 m/s and vertical is 30 m.sCalculate the velocity using the formula V = √[(V2x) + (V2y)]V = √(302)(402)V = √(900 + 1600)V = √2500V = 50 m.s
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? [email protected]
About Force and Motion
Displacement, velocity and acceleration describe motion, including the horizontal and vertical components of projectile motion. The chapter connects these quantities with Newton's laws, momentum and impulse, then applies conservation of momentum to collisions, distinguishing elastic collisions from inelastic ones.
Practise Force and Motion
1,416 free Force and Motion MCQs from Physics, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Discussion
Stuck on an option, or know a faster way to get there? Ask or explain it here.
No comments yet. Be the first to explain this one.
Exams that ask Physics questions like this
Physics is on 16 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
More Force and Motion questions
A missile is fired for maximum range with an initial velocity of 20 m/s. If g=10m/s2, the range of the missle is:
A body covers half of the distance with 2ms-1 and other half with 4ms-1then average speed is:
A body moves from point P(3,4) to Q (5,7). Its displacement vector would be:
The rate of change of momentum of a body falling freely under gravity is equal to its:
At 10 kg object collides with stationary 5 kg object and after collision they stick together and move forward with velocity 4ms-1What is the velocity with which the 10 kg object hit the second one?
A force of 10 N acts on a body of mass 20 kg for 10 seconds. The change in its momentum is;