A Pebble of mass 0.05 kg is thrown vertically upwards. Give the direction and magnitude of the net force on the pebble.
a. during its upward motion
b. during its downward motion
c. at the highest point where it is momentarily at rest.
Does your answer change if the pebble was thrown at an angle of 45° with the horizontal direction? Ignore air resistance.
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Hii dear,
# Answer- 0.5 N everywhere.
# Explaination-
(a) In all three cases i.e. upwards, downwards and at highest point the only force acting on pebble is gravitational force.
At any point, acceleration due to gravity always acts downwards with magnitude g = 9.8 m/s^2.
Gravitational force is given by,
F = ma = mg
F = 0.05×10
F = 0.5 N.
Hence, force of 0.5 N in downwards direction will act on pebble everywhere.
(b) When angle is 45°-
Velocity of the pebble will have 2 components, veetical component and horizontal component.
But horizontal component doesn't affect force, hence net force will be due to vertical component only. i.e. 0.5 N
Hope that is useful.
# Answer- 0.5 N everywhere.
# Explaination-
(a) In all three cases i.e. upwards, downwards and at highest point the only force acting on pebble is gravitational force.
At any point, acceleration due to gravity always acts downwards with magnitude g = 9.8 m/s^2.
Gravitational force is given by,
F = ma = mg
F = 0.05×10
F = 0.5 N.
Hence, force of 0.5 N in downwards direction will act on pebble everywhere.
(b) When angle is 45°-
Velocity of the pebble will have 2 components, veetical component and horizontal component.
But horizontal component doesn't affect force, hence net force will be due to vertical component only. i.e. 0.5 N
Hope that is useful.
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