Mechanics

Kinetic energy is calculated using the formula KE = 0.5 * m * v^2. Substituting 1 kg for mass and 10 m/s for velocity yields 0.5 * 1 * 100, which equals 50 J. Option C is incorrect because it fails to multiply by the factor of 1/2, while option A mistakenly omits squaring the velocity.

In uniform circular motion, the speed remains constant because the net force acts perpendicular to the direction of motion, doing no work. Option A is incorrect because velocity is a vector, and its continuously changing direction means the velocity is not constant.

The Newton is the SI unit of force, defined as the force needed to accelerate a one-kilogram mass at one meter per second squared. A diagram for this topic isn't available yet — the worked example below walks the same reasoning step by step.

• !Option A is incorrect because the Pascal is the SI unit of pressure, representing force per unit area rather than force itself.
• !Option A is incorrect because velocity is a vector, and its continuously changing direction means the velocity is not constant.
• !Option C is incorrect because multiplying mass by gravity gives the gravitational force in Newtons, not the acceleration.
• !Option C is incorrect because it fails to multiply by the factor of 1/2, while option A mistakenly omits squaring the velocity.
• !Option A is incorrect because mass multiplied by acceleration defines force under Newton's second law, not momentum.

Answer each from memory — you'll see instantly whether you're right and why.

Run a focused 10-question mini-mock on Mechanics and see it stick.