This is the 2959th most frequent Chinese word.
用力
"用力" means "to exert force" or "to use strength."
用力 in this context emphasizes the strong effort applied in performing the action of pushing.
他用力推开了门。
He pushed the door open with force.
用力 is used here to emphasize the necessity of applying strength or force to securely hold the rope.
用力握住绳子以防滑落。
Grip the rope firmly to prevent slipping.
用力 in this sentence advises moderation in applying force or effort during running, suggesting balance.