JEE Main 2024 Physics question
A train starting from rest first accelerates uniformly up to a speed of 80 km/h for time t, then it moves with a constant speed for time 3t. The average speed of the train for this duration of journey will be (in km/h):
Answer: (B)
Solution
Distance = ½(80)t + 80(3t) = 280t over a time 4t, so the average speed is 70 km/h.