A cannonball is shot from a cannon at a launch angle of 35 and an initial velocity of 147 m/s. The gravitational acceleration is -9.8 m/s^2. Assuming NO air resistance, how long will it take the cannonball to reach the peak of its trajectory? A.)9.8 s
B.)40.2 s
C.)26.7 s
D.)8.6 s

As part of your daily workout, you lie on your back and push with your feet against a platform attached to two stiff springs arranged side by side so that they are parallel to each other. when you push the platform, you compress the springs. you do an amount of work of 79.0 j when you compress the springs a distance of 0.230 m from their uncompressed length. (a) what magnitude of force must you apply to hold the platform in this position? (b)how much additional work must you do to move the platform a distance 0.230 m farther? (c) what maximum force must you apply to move the platform a distance 0.230 m farther?