# Search results

1. ### Molar specific heat of an ideal gas

Homework Statement A sample of a diatomic ideal gas has pressure P and volume V. When the gas is warmed, it's pressure triples and the it's volume doubles. This warming process includes two steps, the first at constant pressure and the second at constant volume. Determine the energy...
2. ### Refrigerator and Heat Pump

Homework Statement A freezer has a coefficient of performance of 6.30. It is advertised as using electricity at a rate of 457kWh/yr. a)On average how much energy does it use in a single day? b) What maximum mass of water at 20.0 degree celsius could the freezer freeze in a single day...
3. ### Calculating final pressure

Homework Statement As a 1.00 mol sample of a monoatomic gas expands adiabatically the work done on it is -2.50x10^3J. The initial temperature and pressure of the gas are 500k and 3.60atm. Calculate a. The final temperature and b. The final pressure. Homework Equations First law...
4. ### Center of mass for a raft

Homework Statement A square uniform raft, 18m by 18m of mass 6200kg is used as a ferry boat. if three cars each of mass 1350 kg occupy the NE, SE, and SW corners, determine the Centre of mass of the loaded ferryboat relative to the centre of the raft Homework Equations Center of mass...
5. ### Mechanical energy- Falling rock

Homework Statement If the original height of a falling rock is y1 = h = 3.0m; calculate the rock's speed just before it hits ground. Homework Equations From conservation of mechanical energy law 1/2mv1^2 + mgy1 = 1/2mv2^2 + mgy2 The Attempt at a Solution I think i'm supposed to find v2 i.e...
6. ### Calculating Work done

Homework Statement A box of mass 6.0kg is accelerated from rest by a force across the floor at a rate of 2.0m/s for 7.0s. Find the net work done on the box. Homework Equations Work done = Force x distance The Attempt at a Solution F = ma F = 6 x 2 = 12N i solved for final...
7. ### Projectile motion of a kicked ball

Homework Statement A ball is kicked in the air with an initial velocity of 15m/s at an angle of 37 degrees; 0.8 m above the ground. How long is the ball in the air???? Homework Equations The Attempt at a Solution I resolved the vector into its components and the y component was...
8. ### Vector and magnitude problem

Homework Statement A little assistance with this question:- A vector, B, when added to the vector C = 3i + 4j yields a resultant vector which is in the positive y direction and has a magnitude equal to that of C. What is the magnitude of B? Homework Equations The Attempt at a...
9. ### Motion in one dimension

Homework Statement A car travels north at 30 m/s for one half hour. It then travels south at 40 m/s for 15 minutes. The total distance the car has traveled and its displacement are??? Homework Equations The Attempt at a Solution First of all i converted from m/s to km/h. I...
10. ### Motion in one dimension

Hello, please any help will be very much appreciated; A bullet is fired through a board, 14.0 cm thick, with its line of motion perpendicular to the face of the board. If it enters with a speed of 450 m/s and emerges with a speed of 220 m/s, what is the bullet's acceleration as it passes...