Which three options are true about motion in a straight line.
A. A particle which moves at an increasing velocity has a constant acceleration.
B. If two particles always have the same velocity as each other, their separation does not change.
C. A particle which has zero acceleration moves with constant velocity or is stationary.
D. A particle with negative position must have had a negative acceleration in the past.
E. The acceleration of any subject is 9.8m s^-2
F. A particle which moves with a constant acceleration also has a constant velocity.
G. An object which is dropped and falls only under gravity accelerates downwards at approximately 9.8m s^-2
H. Velocity is the magnitude of the speed.
I think b and h??
A, C, G are the answers.
i thought H? Velocity is the magnitude of the speed?
Can you explain why A, C & G. Please, so I can understand
C, G and H are true. A is not true.
To determine which options are true about motion in a straight line, let's analyze each option one by one.
A. A particle which moves at an increasing velocity has a constant acceleration.
This statement is not true. The acceleration of a particle is the rate at which its velocity changes, and if the velocity is increasing, it means the acceleration is not constant. Acceleration is only constant when the velocity changes at a fixed rate over time.
B. If two particles always have the same velocity as each other, their separation does not change.
This statement is not one of the given options.
C. A particle which has zero acceleration moves with constant velocity or is stationary.
This statement is true. When the acceleration of a particle is zero, it means there is no change in velocity. The particle either moves with a constant velocity in a straight line or remains stationary.
D. A particle with negative position must have had a negative acceleration in the past.
This statement is not true. The position of a particle tells us about its location, and it can be either positive or negative depending on the chosen reference point. The position does not directly indicate the past acceleration of the particle.
E. The acceleration of any subject is 9.8 m/s^2.
This statement is not true. The value 9.8 m/s^2 is the acceleration due to gravity on Earth's surface. Acceleration can vary depending on the specific circumstances and forces acting on an object.
F. A particle which moves with a constant acceleration also has a constant velocity.
This statement is not one of the given options.
G. An object which is dropped and falls only under gravity accelerates downwards at approximately 9.8 m/s^2.
This statement is true. When an object falls freely under the influence of gravity only, it accelerates downwards at a rate of approximately 9.8 m/s^2. This acceleration is commonly referred to as the acceleration due to gravity.
H. Velocity is the magnitude of the speed.
This statement is true. Velocity is a vector quantity that describes both the magnitude (speed) and the direction of motion. The magnitude of the velocity is equal to the speed.
Based on the explanations provided, the correct options are C, G, and H.