Answer:
Time, t = 4.08 secs
Explanation:
<u>Given the following data;</u>
Initial velocity, U = 40m/s
To find the time, we would use the first equation of motion;
Where;
- U is the initial velocity.
- t is the time measured in seconds.
<em>Making time, t the subject of formula, we have;</em>
We know that acceleration due to gravity, g is 9.8m/s².
a = g = - 9.8m/s² because the ball is thrown in the opposite direction.
Also, the final velocity is equal to zero (0) because the ball reached its maximum height.
<em>Substituting into the equation, we have;</em>
Time, t = 4.08 secs
<em>Therefore, it will take the ball 4.08 seconds to reach the top. </em>
Answer:
His speed, in metres per second, is approximately 10m/s. The correct option is B.
Explanation:
Speed is defined as the rate in which an object cover a distance in a given time. It is measured in meters per second ( m/s). From the question, the jogger covered a distance of 3Km which when converted to meter is 3000meters in a given time 5 minutes which is 300seconds. The calculation of his speed in meter per second is shown below:
Distance= 3Km to meters ( as 1000meters = 1Km). Therefore 3× 1000 = 3000m
Time= 5 minutes to seconds ( as 1 minute = 60 Seconds). Therefore 5× 60= 300.
Speed= distance/ time
= 3000/300
= 10m/s
Therefore his speed, in metres per second, is approximately 10.
Answer:
Bridget is transferring energy to the bicycle.
The bicycle is using energy to do work.
Bridget has kinetic energy.
The bicycle has potential energy.
The bicycle has mechanical energy.
Explanation:
Energy can be transformed from one form to another. A body possess kinetic energy due to virtue of its motion. Potential energy is possessed by a body due to virtue of its position. mechanical energy is the sum of potential energy and kinetic energy. Nuclear energy is produced when atoms split or two atoms fuse together.
When Bridget is riding bicycle up a hill. Energy involved is both kinetic energy due to motion and potential energy due to gain in height up the hill. Bridget is pedaling, hence he is transferring energy to the bicycle. Bridget is in motion along with the bicycle. Hence, both Bridget and Bicycle have kinetic energy and potential energy. We can say both have mechanical energy. Thus correct options are:
Bridget is transferring energy to the bicycle.
The bicycle is using energy to do work.
Bridget has kinetic energy.
The bicycle has potential energy.
The bicycle has mechanical energy.
Words less true are seldom if ever spoken.
