Home
Class 12
MATHS
A motor powers a model car so that after...

A motor powers a model car so that after starting from rest, the car travels s inches in t seconds, where `s = 16tsqrtt` . Which of the following gives the average speed of the car, in inches per second, over the first t seconds after it starts?

A

`4sqrtt`

B

`16sqrtt`

C

`16/sqrtt`

D

`16t`

Text Solution

Verified by Experts

The correct Answer is:
B
The average speed of the model car is found by dividing the total distance traveled by the car by the total time the car traveled. In the first t seconds after the car starts, the time changes from 0 to t seconds. So the total distance the car traveled is the distance it traveled at t seconds minus the distance it traveled at 0 seconds. At 0 seconds, the car has traveled 16(0) `sqrt0` inches, which is equal to 0 inches. According to the equation given, after t seconds, the car has traveled `16tsqrtt` inches . In other words , after the car starts , it travels a total of `16tsqrtt` inches in t seconds. Dividing this total distance traveled by the total time shows the car's average speed : `(16tsqrtt)/t=16sqrtt` inches per second.
Choices A, C, and D are incorrect and may result from misconceptions about how average speed is calculated.
Promotional Banner

Similar Questions

Explore conceptually related problems

The front of a roller-coaster car is at the bottom of a hill and is 15 feet above the ground. If the front of the roller-coaster car rises at a constant rate of 8 feet per second, which of the following equations gives the height h, in feet, of the front of the roller-coaster car s seconds after it starts up the hill?

A car travels 40 km in the first hour, 45 km in the second hour, and 35 km in the third hour. Calculate the average speed of the vehicle in km/h and m/s.

A car traveled at 80 mph for the first half of the time of a trip and at 40 mph for the second half of the trip. What is the average speed of the car during the entire trip?

A car travels along a straight line for first half time with speed 40 km//h and the second half time with speed 60 km//h . Find the average speed of the car.

A particle starting from rest moves in a straight line with acceleration as shown in the a-t graph. Find the distance (in m) travelled by the particle in the first four seconds from start of its motion. Q

A car starts from rest and moves with uniform acceleration for time t then it moves with uniform speed of 60 km/h for time 3t and comes to rest. Find the average speed of car in its total journey.

A particle starts moving from position of rest under a constant acceleration. If it travels a distance x in t second, what distance will it travel in next t second?

If an object is dropped from a tall building , then the distance it has fallen after t seconds is given by d(t)=16t^2 . Find its average speed , in feet per second, between t=1 second and t=5 seconds.

A car starts from erest accelerates uniform by for 4 second and then moves with uniform velocity which of the x-t graph represent th motion of the car:-

A car travels the first half of a distance between two places a speed of 30 km/hr and the second half of the distance a 50 km/hr. The average speed of the car for the whole journey is