14. After finishing her homework, Sue climbs up a 5.00 m high flight of stairs to her bedroom
Find the magnitude of Sue's weight
and how much
work Sue does in climbing the stairs if she
has a mass of 50.0 kg? (4.90 x 2 N, 2450J)
Explanation:
Given parameters:
Height = 5m
Mass of Sue = 50kg
Unknown:
Magnitude of Sue's weight = ?
Work done by Sue = ?
Solution:
Weight is the vertical force exerted by a body in the presence of gravity.
Mathematically;
W = mg
m is the mass
g is the acceleration due to gravity = 9.8m/s²
Weight = 50 x 9.8 = 490N
Work done = Force x distance = weight x height
Work done = 490 x 5 = 2450J
1. A 75.0 kg man pushes on a 500,000kg wall for 250s but it does not move. How
much work does he do on the wall?
Answer:
0J
Explanation:
No work is being done on the wall by the man pushing on it.
Given parameters:
Mass of man = 75kg
Mass of wall = 500000kg
Time = 250s
Unknown:
Work done = ?
Solution:
Work done is the force applied on a body that moves it along a particular path.
For work to be done, distance must be move or displacement must occur.
Since the wall is not moving the distance is 0;
Work done = Force x distance
Since distance is 0m, work done is 0J
The work done on the wall by the man is 0 J.
To calculate the amount of work done by the man, we use the formula below.
Formula:
W = (ma)d............. Equation 1Where:
W = Work done on the wall by the manm = mass of the walla = acceleration of the walld = distance.from the question,
Given:
m = 500000 kga = 0 m/s² (not moving)d = 0 m.Substitute these values into equation 1
W = 500000(0)(0)W = 0 J.Hence, the work done on the wall by the man is 0 J.
Learn more about work done here: https://brainly.com/question/8119756
Q2. You push a crate up a ramp with a force of 10 N. Despite your pushing, the crate slides down the ramp 4 m. How much work did you do
Answer:
40 J
Explanation:
From the question given above, the following data were obtained:
Force (F) = 10 N
Distance (s) = 4 m
Workdone (Wd) =?
Work done is simply defined as the product of force and distance moved in the direction of the force. Mathematically, we can express the Workdone as:
Workdone = force × distance
Wd = F × s
With the above formula, we can obtain the workdone as follow:
Force (F) = 10 N
Distance (s) = 4 m
Workdone (Wd) =?
Wd = F × s
Wd = 10 × 4
Wd = 40 J
Thus, 40 J of work was done.
An automobile which set the world record for acceleration increase speed from rest to 96 km/h in 3.07 seconds what distance traveled by the time the final speed was achieved
Answer:
41.02m
Explanation:
Given parameters:
Initial velocity = 0m/s
Final velocity = 96km/hr
Time taken = 3.07s
Unknown:
Distance traveled by the time the final speed was achieved = ?
Solution:
To solve this problem, we first find the acceleration of the car;
Acceleration = [tex]\frac{v - u }{t}[/tex]
v is the final velocity
u is the initial velocity
t is the time taken
Now convert the the final velocity to m/s;
96km/hr to m/s;
1 km/hr = 0.278m/s
96km/hr = 96 x 0.278 = 26.7m/s
Now;
Acceleration = [tex]\frac{26.7 - 0}{3.07}[/tex] = 8.69m/s²
So;
v² = u² + 2as
v is the final velocity
u is the initial velocity
a is the acceleration
s is the distance
26.7² = 0² + 2 x 8.69 x s
712.89 = 17.38s
s = 41.02m