Physics - Study Mode

[#476] Negative acceleration is in the opposite direction of:
Correct Answer

(C) Velocity

Explanation

Solution: When an object is slowing down, the acceleration is in the opposite direction as the velocity. Thus, this object has a negative acceleration. When an object is speeding up, the acceleration is in the same direction as the velocity. Thus, this object also has a negative acceleration.

[#477] If an object moves with constant velocity,
Correct Answer

(C) It must have constant speed in constant direction

Explanation

Solution: When an object is moving with constant velocity, it does not change direction nor speed and therefore is represented as a straight line when graphed as distance over time. You can also obtain an object's velocity if you know its trace over time.

[#478] In uniform circular motion, the linear velocity is perpendicular to
Correct Answer

(C) Radius vector

Explanation

Solution: In uniform circular motion, the linear velocity is perpendicular to radius vector.

[#479] Flywheel is an important part of a steam engine because it :
Correct Answer

(B) Helps the engine in keeping the speed uniform

Explanation

Solution: A flywheel is a rotating mechanical device that is used to store rotational energy. Flywheels have a significant moment of inertia and thus resist changes in rotational speed, enabling the engine to run at a constant, uniform motion. In the Industrial Revolution, James Watt contributed to the development of the flywheel in the steam engine.

[#480] The following particles move with same kinetic energy. Which of them has maximum momentum ?
Correct Answer

(D) Alpha Particle

Explanation

Solution: Since alpha particle has higher mass than electron, proton and deuteron, its momentum will be maximum.