Mechanics

171.If a body is 11.2 km from the earth. If thrown with a velocity per second, then the body-
 
A. Never return to earth
 
B. Will return after 2 hours
 
C. Will return after 24 hours
 
D. Not certain
 
Option”A” is correct
172.When a stone is brought from the surface of the moon to the earth, then
 
A. Its mass will change
 
B. Its volume will change, but not the mass
 
C. Both weight and mass will change
 
D. Neither mass nor weight will change
 
Option”B” is correct
173.When a person sitting in a lift feels his weight more
 
A. When the lift is coming down at high speed
 
B. When the lift is going up at high speed
 
C. Coming down at the same rate
 
D. Going up with the same velocity
 
Option”B” is correct
174.Around the Earth: Ball dropped out of orbiting artificial satellite
 
A.  Will go to earth
 
B. Will go to the moon
 
C. Will fall to earth
 
D. Around the Earth: Will rotate in its orbit with the same period as the satellite
 
Option”D” is correct
175.The direct weight of a person in a lift is less than when the lift is going-
 
A. Up with acceleration
 
B. Down with acceleration
 
C. Up with the same speed
 
D. Down at the same speed
 
Option”B” is correct
176.What is the approximate height of a synchronous satellite from the surface of the earth?
 
A. 36000 KM
 
B. 42000 KM
 
C. 30000 KM
 
D. None of these
 
Option”A” is correct
177.Tennis ball bounces higher on a hill than on the ground. Because-
 
A. The air pressure is relatively less on the mountains
 
B. The ball gets lighter in the mountains
 
C. Earth’s acceleration due to gravity decreases over mountains
 
D. None of the above
 
Option”C” is correct
178.If the gravitational force of the earth suddenly vanishes, which of the following consequences would be true?
 
A. The weight of the object will be zero, but the mass will remain the same
 
B. The mass of the object will become zero, but the volume will remain the same
 
C. Both the weight and mass of the object will become zero
 
D. The mass of the object will increase
 
Option”A” is correct
179.What fraction of Earth’s gravity is closest to the Moon’s gravity?
 
A. 1/5′
 
B. 1/4′
 
C. 1/6′
 
D. 1/8′
 
Option”C” is correct
180.Time period of pendulum
 
A. Depends on mass
 
B. Depends on length
 
C. Depends on the temperature
 
D. Depends on time
 
Option”B” is correct