Mechanical revision
F40 BMA
Tutorial 4
1.
A man is driving at 120 km/h along a straight road and he looks to the side for 2.0 s, how far does he travel during this inattentive period?
[66.7 m]
2.
A horse canters away from its trainer in a straight line, moving 160 m away in 17.0 s.
It then turns abruptly and gallops halfway back in 6.8 s. Calculate (a) its average speed and (b) its average velocity for the entire trip, using “away from the trainer” as the positive direction. [10.1 m/s; 3.36 m/s]
3.
A car traveling 90 km/h is 100 m behind a truck traveling 75 km/h. How long will it take the car to reach the truck? [24.0 s]
4.
An airplane travels 2100 km at a speed of 800 km/h, and then encounters a tailwind that boost its speed to 1000 km/h for the next 1800 km. What was the total time for the trip? What was the average speed of the plane for this trip? [4.43 h; 880 km/h]
5.
In coming to a stop, a car leaves skid marks 75 m long on the highway.
Assuming a deceleration of 7.00 m/s2, estimate the speed of the car just before braking. [32.4 m/s]
6.
Determine the stopping distances for an automobile with an initial speed of 90 km/h and human reaction time of 1.0 s: (a) for an acceleration a = –4.0 m/s2; (b) for a = –
8.0 m/s2. [103 m; 64.1 m]
7.
A ball is hit almost straight up into the air with a speed of about 20 m/s. (a) How high does it go? (b) How long is it in the air? [20.4 m; 4.08 s]
8.
A helicopter is ascending vertically with a speed of 5.20 m/s. At a height of 110 m above the Earth, a package is dropped from a window. How much time does it take for the package to reach the ground? [5.30 s]
9.
A stone is thrown vertically upward with a speed of 25.0 m/s. (a) How fast is it moving when it reaches a height of 12.0 m? (b) How much time is required to reach this height? (c) Why are there two answers to (b)? [19.7 m/s; 0.537 s; 4.57 s]
10.
A shotputter throws the shot (mass = 7.2 kg) with an initial speed
Tutorial 4
1.
A man is driving at 120 km/h along a straight road and he looks to the side for 2.0 s, how far does he travel during this inattentive period?
[66.7 m]
2.
A horse canters away from its trainer in a straight line, moving 160 m away in 17.0 s.
It then turns abruptly and gallops halfway back in 6.8 s. Calculate (a) its average speed and (b) its average velocity for the entire trip, using “away from the trainer” as the positive direction. [10.1 m/s; 3.36 m/s]
3.
A car traveling 90 km/h is 100 m behind a truck traveling 75 km/h. How long will it take the car to reach the truck? [24.0 s]
4.
An airplane travels 2100 km at a speed of 800 km/h, and then encounters a tailwind that boost its speed to 1000 km/h for the next 1800 km. What was the total time for the trip? What was the average speed of the plane for this trip? [4.43 h; 880 km/h]
5.
In coming to a stop, a car leaves skid marks 75 m long on the highway.
Assuming a deceleration of 7.00 m/s2, estimate the speed of the car just before braking. [32.4 m/s]
6.
Determine the stopping distances for an automobile with an initial speed of 90 km/h and human reaction time of 1.0 s: (a) for an acceleration a = –4.0 m/s2; (b) for a = –
8.0 m/s2. [103 m; 64.1 m]
7.
A ball is hit almost straight up into the air with a speed of about 20 m/s. (a) How high does it go? (b) How long is it in the air? [20.4 m; 4.08 s]
8.
A helicopter is ascending vertically with a speed of 5.20 m/s. At a height of 110 m above the Earth, a package is dropped from a window. How much time does it take for the package to reach the ground? [5.30 s]
9.
A stone is thrown vertically upward with a speed of 25.0 m/s. (a) How fast is it moving when it reaches a height of 12.0 m? (b) How much time is required to reach this height? (c) Why are there two answers to (b)? [19.7 m/s; 0.537 s; 4.57 s]
10.
A shotputter throws the shot (mass = 7.2 kg) with an initial speed