Answer:
A) It takes the truck 8 s to catch the motorcycle.
B) The motorcycle has traveled 160 m in that time.
C) The velocity of the truck is 40 m/s at that time.
Explanation:
The equations of the position and velocity of an object moving in a straight line are as follows:
x = x0 +v0 · t + 1/2 · a · t²
v = v0 + a · t
Where:
x = position
x0 = initial position
v0 = initial velocity
t = time
a = acceleration
v = velocity at time t
(A) When the the truck catches the motorcycle, both have the same position. Notice that the motorcycle moves at constant speed so that a = 0:
x truck = x motorcycle
x0 +v0 · t + 1/2 · a · t² = x0 + v · t
Placing the origin of the frame of reference at the point where the truck starts, both have an initial position of 0. The initial velocity of the truck is 0. Then:
1/2 · a · t² = v · t
solving for t:
t = 2 v/a
t = 2 · 20 m/s/ 5 m/s²
t = 8 s
It takes the truck 8 s to catch the motorcycle.
(B) Using the equation of the position of the motorcycle, we can calculate the traveled distance in 8 s.
x = v · t
x = 20 m/s · 8 s
x = 160 m
(C) Now, we use the velocity equation at time 8 s.
v = v0 + a · t
v = 0 m/s + 5 m/s² · 8 s
v = 40 m/s
Hi there!
Great question!
Basketballs have air inside them. A special pump is used to insert the air. That's why you can lift the basketballs off the ground easily. If it was a solid, though, you'd hardly be able to lift the ball up! Basketballs can float, too, because anything with air inside can float. If it were solid, it would sink in the water easily.
Hope this helps! :D
If you rub a glass rod with a cloth, the charge produced on the glass rod is called positive, whereas when a plastic rod is rubbed with a cloth, the charge produced on the plastic rod is negative.
Answer:
Electric Motor
Explanation:
There are mainly two types of machines for inter-conversion between mechanical energy and electrical energy as under:
- Motor
- Generator
Motor is a device which converts electrical energy into a mechanical whereas generator does the exact opposite of motor.
There are 2 types of motors:
AC Motor - Converts alternating current into mechanical energy
DC Motor - Converts direct current into mechanical energy
Answer:
the body has linear acceleration, but cannot rotate
Explanation:
Let's analyze the system
If the torque is zero, the two forces are the same magnitude, but applied to each side of the body in such a way that the torque cancels the punch of the other. Therefore the body cannot turn
The two forces go in the same direction so the object can have linear acceleration
The object is at rest because it has a force in the same direction, but in the opposite direction.
therefore the correct answer is:
the body has linear acceleration, but cannot rotate
