Advertisements
Advertisements
प्रश्न
A man throws a ball weighing 500 g vertically upwards with a speed of 10 m/s.
- What will be its initial momentum ?
- What would be its momentum at the highest point of its flight ?
Advertisements
उत्तर
(i) We know that:
Momentum = mass × velocity
= m × v
Here, mass, m = 500 g
We can convert grams (g) to kilograms (kg). A kilogram has 1000 grams.
m = 500 / 1000
m = 0.5 kg
Also, velocity, v =10 m/s
Putting these values in the above formula, we get:
Momentum = 0.5 × 10 = 5 kg.m/s
(ii) Its momentum at the highest point of its flight would be zero. At the maximum height the velocity of the ball is zero.
APPEARS IN
संबंधित प्रश्न
Figure shows a man standing stationary with respect to a horizontal conveyor belt that is accelerating with 1 m s–2. What is the net force on the man? If the coefficient of static friction between the man’s shoes and the belt is 0.2, up to what acceleration of the belt can the man continue to be stationary relative to the belt? (Mass of the man = 65 kg.)
A stream of water flowing horizontally with a speed of 15 m s–1 gushes out of a tube of cross-sectional area 10–2 m2, and hits a vertical wall nearby. What is the force exerted on the wall by the impact of water, assuming it does not rebound?
What is the total momentum of the bullet and the gun before firing ?
Name the physical quantity whose unit is kg.m/s.
Explain the meaning of the following equation : .
p = m x v
where symbols have their usual meanings.
Define momentum of a body. On what factors does the momentum of a body depend ?
Name the law involved in the following situation :
the sum of products of masses and velocities of two moving bodies before and after their collision remains the same.
A man wearing a bullet-proof vest stands still on roller skates. The total mass is 80 kg. A bullet of mass 20 grams is fired at 400 m/s. It is stopped by the vest and falls to the ground. What is then the velocity of the man?
Two billiard balls A and B, each of mass 50 g and moving in opposite directions with speed of 5 ms–1 each, collide and rebound with the same speed. If the collision lasts for 10–3 s, which of the following statements are true?
- The impulse imparted to each ball is 0.25 kg ms–1 and the force on each ball is 250 N.
- The impulse imparted to each ball is 0.25 kg ms–1 and the force exerted on each ball is 25 × 10–5 N.
- The impulse imparted to each ball is 0.5 Ns.
- The impulse and the force on each ball are equal in magnitude and opposite in direction.
Two blocks P and Q of masses 0.3 kg and 0.4 kg, respectively, are stuck to each other by some weak glue as shown in the figure. They hang together at the end of a spring with a spring constant of k = 200 N/m. The block Q suddenly falls free due to the failure of glue, then the maximum kinetic energy of block P during subsequent motion will be ______ mJ.
