Alejandra does 3375 Joules of work against gravity when she climbs to the ledge at the top of the climbing wall.
In order to calculate the work done against gravity, we can use the formula: Work = Force x Distance. The force of gravity can be calculated using the equation: Force = mass x acceleration due to gravity. Given that Alejandra weighs 225 newtons and the distance she climbs is 15 meters, we can plug these values into the formula to find the work done:
Work= (225 N) x (15 m) = 3375 Joules
Therefore, Alejandra does 3375 Joules of work against gravity when she climbs to the ledge at the top of the climbing wall.
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Answer:
The speed of the car is or .
Further Explanation:
Given:
The distance covered by the car is .
The time taken by the car to cover the distance is .
Concept:
The speed of a car is the ratio of the distance covered by the car to the time taken by the car in covering the distance.
The expression for the speed of the car is:
…… (1)
Here, is the speed of the car, is the distance covered and is the time taken by the car.
Substitute the value of distance and time in the above expression.
The speed of the car in terms of can be expressed as.
Thus, the speed of the car is or .
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Answer Details:
Grade:Middle School
Chapter:Speed and distance
Subject:Physics
Keywords:Speed, velocity, distance, time, distance of 150 km, in 7200 s, speed of the car, ratio of distance, rate of change of distance.
Answer:
t = 10.4 s
Explanation:
given,
velocity of the police car = 18 m/s
reaction time of policeman = 0.8 s
acceleration of the policeman to catch up the speeder = 5 m/s²
time taken to catch the speeder be t₁
distance traveled by the police and the speeder will be same
t₁ = 9.6 s
total time taken by the policeman
= reaction time + t₁
= 0.8 + 9.6
t = 10.4 s
Total time taken by the policeman to catch the speeder is 10.4 s
Answer:
The potential energy can be given as
E = mgh. m is mass, g = acceleration due to gravity = 9.8m/s, h is the heigh, given as 100.0m
E = m x 9.8 x 100 = (980m)J
E = (980m)/10^9GJ = (0.000000980m)GJ to 3 significant figures
Explanation:
Hydroelectric dams exploit storage of gravitational potential energy. A mass, m, raised a height, h against gravity, g = 9.8 m/s², is given a potential energy E = mgh. The result will be in Joules if the input is expressed in meters, kilograms, and seconds (MKS, or SI units).
Answer:mass
Explanation: