Answer:
Approximately
.
Explanation:
Make use of the fact that total momentum is conserved in collisions.
The momentum of an object of mass
and velocity
is
.
The momentum of the two trolleys before the collision would be:
.
.
Thus, the total momentum of the two trolleys right before the collision would be
.
Since the two trolleys are stuck to one another after the collision, they could modelled as one big trolley of mass
.
The momentum of the two trolleys, combined, is conserved during the collision. Thus, the total momentum of the new trolley of mass
would continue to be
shortly after the collision.
Rearrange the equation
to find the velocity of the two trolleys combined:
.
Answer:
1) 0.51 seconds.
2) 1.45 m/s.
Explanation:
given, height from which cat falls = 1.3 m
we know that, s = ut +
at².
here if we consider cat moment only in downward direction,
intial velocity of cat in downward direction , u = 0.
so, time, t =
.
⇒ t =
= 0.51 seconds.
t = 0.51 seconds.
now, consider cat moment only in forward direction
s = ut , since acceleration is zero in forward direction
⇒ u =
.
so, u =
= 1.45 m/s .
Mike enters a revolving door that is not moving. Mike should
push at the edge of the door where it is largest distance from the pivot point
in order to produce a torque with the least amount of force. Torque is equal to
t = force x distance.
Answer:
The average velocity that these birds travel is 122.22 miles per day to the south.
Explanation:
Speed is the physical quantity that expresses the variation in position of an object and as a function of time. In other words, speed is a physical quantity that expresses the relationship between the space traveled by an object, the time used for it and its direction.
Speed is expressed mathematically as the quotient between distance and time:

where "v" is the speed of the mobile, "d" is the distance traveled by the mobile, and "t" is the time taken by the mobile to carry out the movement.
In this case:
- d= 11,000 miles
- t=3 months= 90 days (
considering that in 1 month there are 30 days)
Replacing:

velocity = 122.22 
<u><em>The average velocity that these birds travel is 122.22 miles per day to the south.</em></u>
Answer:
Explanation:
The formula for centripetal acceleration is
. Filling in:
and
so
v = 6.1 m/s