Let's assume that Zoey ran at a constant speed. we can use the equation,
d = st
where, d = distance, s = speed, and t = time taken.
By rearranging,
s = d/t
Zoey had travelled 100 m in 20 seconds.
Hence, s = 100 m / 20 s = 5 m/s
therefore Zoey's speed at 100 m is 5 m/s
The distance from Buzău to Iaşi is 72 km. Find out the time a vehicle travels this distance if it has a speed of 72 km per hour. Expresses the speed in the unit of measurement in SI. I give the crown! Thank you
Answer:
3600seconds
Explanation:
Given parameters:
Distance = 72km
Speed = 72km/hr
Unknown:
Time it takes for the vehicle to travel the distance = ?
Solution:
Speed is the distance divided by time;
Speed = 
time =
Insert the parameters;
time =
= 1hr
The SI unit of time is in seconds;
3600 seconds is 1hr
The time is 3600seconds
Answer:
6 m/s is the missing final velocity
Explanation:
From the data table we extract that there were two objects (X and Y) that underwent an inelastic collision, moving together after the collision as a new object with mass equal the addition of the two original masses, and a new velocity which is the unknown in the problem).
Object X had a mass of 300 kg, while object Y had a mass of 100 kg.
Object's X initial velocity was positive (let's imagine it on a horizontal axis pointing to the right) of 10 m/s. Object Y had a negative velocity (imagine it as pointing to the left on the horizontal axis) of -6 m/s.
We can solve for the unknown, using conservation of momentum in the collision: Initial total momentum = Final total momentum (where momentum is defined as the product of the mass of the object times its velocity.
In numbers, and calling
the initial momentum of object X and
the initial momentum of object Y, we can derive the total initial momentum of the system: 
Since in the collision there is conservation of the total momentum, this initial quantity should equal the quantity for the final mometum of the stack together system (that has a total mass of 400 kg):
Final momentum of the system: 
We then set the equality of the momenta (total initial equals final) and proceed to solve the equation for the unknown(final velocity of the system):

Answer:
900 W.
Explanation:
Given that
Electric heater 1500 W
We know that power P given as
P= V I
So the total power of 120 V and 20 A circuit
P = 120 x 20
P= 2400 W
So the power new load P'
P'= Total system power(P)- Electric heater load
P ' = 2400 - 1500
P'= 900 W
So the answer is 900 W.