Q. What was the initial speed of a car if its speed is 40sm after 5 seconds of accelerating at 4s2m ?A. 20smB. 60smC. 10smD. 25sm
Use Formula for Final Velocity: Let's use the formula for final velocity, which is v=u+at, where v is the final velocity, u is the initial velocity, a is the acceleration, and t is the time.
Identify Known Values: We know the final velocity v is 40m/s, the acceleration a is 4m/s2, and the time t is 5 seconds. We need to find the initial velocity u.
Plug in Values: Plugging the known values into the formula, we get 40m/s=u+(4m/s2×5s).
Calculate Product: Now, we calculate the product of the acceleration and time: 4m/s2×5s=20m/s.
Substitute Values: Substitute the product back into the equation: 40m/s=u+20m/s.
Solve for Initial Velocity: To find the initial velocity u, we subtract 20m/s from both sides of the equation: u=40m/s−20m/s.
Final Answer: After the subtraction, we find that the initial velocity u is 20 m/s.
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